## Summary

Hyprland matches window rule `class` with `RE2::FullMatch`, but the chromium tag rule in `default/hypr/apps/browser.lua` is written as if matching were a substring search. As a result **no web app window ever receives `+chromium-based-browser`**, on any Chromium-family browser, so web apps miss the tile and opacity rules that follow the tag.

This is adjacent to but not covered by #8968, which fixes the *browser* class (`brave-origin`) on the same line. Web app classes stay unmatched even with that PR applied.

## The rule

```lua
o.window("((google-)?[cC]hrom(e|ium)|[bB]rave-browser|[mM]icrosoft-edge|Vivaldi-stable|helium)", { tag = "+chromium-based-browser" })
```

Every alternative is a complete browser class, so the rule works for real browser windows. Web apps launched through `omarchy-launch-webapp` get a Chromium `--app` class of the form `<browser>-<host>__<path>-Default`, which no alternative can full-match.

Matching semantics, for reference (`src/desktop/rule/matchEngine/RegexMatchEngine.cpp` in Hyprland):

```cpp
bool CRegexMatchEngine::match(const std::string& other) {
    return re2::RE2::FullMatch(other, *m_regex) != m_negative;
}
```

## Steps to reproduce

```bash
omarchy-webapp-install "Example" "https://example.com/" "https://example.com/favicon.ico"
gio launch ~/.local/share/applications/Example.desktop
hyprctl clients -j | jq -r '.[] | select(.class | test("example.com")) | "\(.class)  tags=\(.tags)"'
```

Observed, with Chromium as the default browser:

```
chrome-example.com__-Default  tags=["default-opacity*"]
```

And with Brave Origin as the default browser (an Outlook web app):

```
brave-outlook.office.com__mail_-Default  tags=["default-opacity*"]
```

**Expected:** both carry `chromium-based-browser`.
**Actual:** neither does. They fall through to the generic `default-opacity` rule.

Note the first case uses plain Chromium, whose class does contain the literal substring `chrome`. It still misses the tag, which isolates the cause to full-match semantics rather than to any particular browser's naming.

## Consequences

1. Web apps miss `tile = true` and the browser opacity pair `1.0 0.985`, and instead inherit `default-opacity` at `0.985 0.96`. Web app windows are visibly more translucent than browser windows when unfocused, which is most noticeable on text-dense apps such as web mail.
2. These lines further down the same file are dead code, because they remove a tag that was never applied:

   ```lua
   o.window("(^.+-youtube\\.com__.*$|^.+-app\\.zoom\\.us__wc_home.*$)", { tag = "-chromium-based-browser" })
   ```

   Their existence, and their deliberately browser-agnostic `^.+-` prefix, suggests web apps were intended to carry the tag. YouTube and Zoom still end up correct only because the following line drops `default-opacity` from them directly.

## Suggested direction

Match the web app class form alongside the bare browser classes, in the same browser-agnostic spirit as the existing YouTube and Zoom rules, for example by allowing an optional `-<appid>-Default` suffix on the browser alternation. I have not opened a PR since #8968 already touches this line and adds `test/shell.d/browser-tags-test.sh`; folding a web app case into that test seems tidier than a competing change.

## System

- Omarchy 4.0.2-1
- Hyprland 0.56.2
- Chromium 151.0.7922.173
- Brave Origin 152.1.94.117 (`brave-origin-bin` 1:1.94.117-1)